Mexican soldiers have discovered a huge arsenal of weapons and ammunition buried in an underground chamber, apparently hidden by one of the country's warring drug cartels.

Authorities said they found more than 150 rifles and shotguns, 92,000 rounds of ammunition, four mortar shells, two rocket-propelled grenades and assorted other weaponry. The cache was found at a ranch near the industrial city Monclova in the northern state Coahuila that borders the United States.

They believe the cache belonged to the Zetas cartel, which has been battling the Sinaloa cartel and other drug gangs for control of Coahuila.

Mexican authorities have seized more than 102,000 handguns and high-powered rifles in the past four years but some experts believe that 2,000 weapons are being brought into the country each day.

Drug-related violence has become commonplace in Mexico, with about 37,000 people killed since the government launched an anti-drug crackdown in 2006.